The company's Overdrive media console works on Macs and PCs for readers tied to their desktops. It also comes as an app for Android™ , BlackBerry®, iOS and Windows® Phone 7.

According to Jeff Morgan, the marketing and communications and specialist I spoke with, Overdrive also offers secure management, DRM protection, and download fulfillment services for publishers, libraries, schools and retail stores. The company has been around since 1986 and brings years of software development experience to the e-reader market.

Copia also offers apps for e-readers, but it is positioning itself for the virtual book club market. These are the readers who want their content in the cloud--not tied to any one device--and who want to add notes, thoughts and comments to e-books they are reading along with hundreds of others in real time. [Forbes Video Network profiled them in September 2010.]

Chafie Press is promoting interactive books for young readers on iPad. Their customized app, called Immersedition, allows for more interaction than Apple's iBooks app.

While the publisher may branch out to offer its books on other devices, Erica Erwin, whom I spoke with at the Chafie booth, said their target audience right now is the young reader on the iOs devices. Their featured author for the app is Amanda Havard, author of The Survivors.